Proposition 2 [1]}, [2]} 
Let \(M \ge 0\)  and \(\eta \)  be fixed constants, and let \(h(\cdot )\)  be a function defined on a set \(V\)  such that \(\eta \le h(p) \le \eta + M\)  for all \(p \in V\) . Let \(U \subseteq V\)  be a random sample of size \(s\) , and \(\delta > 0\)  be a parameter. If \(s \ge \frac{M^2}{2\delta ^2} \ln (2/\lambda )\) , then
\(\Pr \left[ \left| \frac{h(V)}{|V|} - \frac{h(U)}{|U|} \right| \ge \delta \right] \le \lambda ,\) 
